How to Sink a Marshmallow

Time: 5 to 10 minutes
Skill Level: Medium
The experiment: Marshmallows are filled with air, which makes them float. Can you sink them?

What you need:

Mini marshmallows

Large clear bowl of water

Cornstarch

Flat surface, such as a cutting board, tabletop or counter

Spoon (optional)

What to do:

Drop a marshmallow into the water. Does it sink or float?

Sprinkle cornstarch over your flat surface.

Put the marshmallow on the cornstarch and squash it. Try rolling it, smashing it down or smashing it between your hands. The cornstarch will keep it from getting too sticky.

Put it in water to see if it floats. (If it sticks to your hands, scrape it off with the spoon.)

The more you squash the marshmallow, the lower it will float in the water. If you squash it small enough, it will sink.

If your marshmallow didn’t sink, grab another one and try again!

What’s happening:

When you squash the marshmallow, you make it smaller and denser. The smaller it is, the less water it can push aside, and the lower it floats. If you squash the marshmallow so small that it’s denser than water, it will sink.

More fun:

Can’t sink your marshmallow? Pour a cup of cooking oil, such as vegetable oil, into a bowl, and drop in your marshmallow. Since the oil is less dense than water, the marshmallow is more likely to sink.

If you’re a champion at sinking mini marshmallows, try sinking large marshmallows. Can you beat the challenge?

After a few minutes, look for floating letters. (Some break up as they rise, but a few should survive intact.)

What’s happening:

The white letters on M&M’s, Skittles and Jelly Belly beans are printed with an edible ink that doesn’t dissolve in water. When the rest of the candy shell dissolves, the letters peel off and float.

Hearts Bobbing

Time: 5 minutes
Skill Level: Easy
The experiment: Hearts sink, and hearts float. Can you make them do both?

What you need:

Clear drinking glass

Club soda or clear soda

Conversation hearts or Necco wafers

What to do:

Fill the drinking glass with soda. Put the candies in the glass. Do some of them float? Do they sink again? (If they don’t sink by themselves, tap them with a spoon to knock off the bubbles.)

What’s happening:

Club soda contains carbon dioxide gas. When the carbon dioxide forms bubbles on the candies, the candies start floating. It’s as if they were wearing life jackets. But as the candies rise, the bubbles pop or get knocked off. Without the bubbles, the candies sink back to the bottom. Then bubbles start to form again, and the cycle starts over.

Gummi candies are made with gelatin, a tangle of long protein molecules. (The tangled molecules don’t break apart easily, which makes gummies stretchy.) When you put gelatin in water, the protein pulls the water into the tangle and the candy expands. Eventually, it absorbs so much water that the molecules spread apart and untangle, which makes the candy fall apart more easily.

As the gummi candy absorbs more and more water, it starts to resemble a different kind of gelatin dessert. Jell-O is also made of gelatin, sugar and water. So when you expand your gummi candy, you’re making something like Jell-O

More fun:

If you want to find out how much water your gummi worm absorbed, weigh it before and after the experiment. The added weight is the extra water. (If your gummi candy breaks, try lifting it with a slotted spoon or pouring the water and candy onto a plate.)

Clamshell Skittles

Time: 2 to 5 minutes
Skill Level: Get a grown-up
The experiment: Can you crack Skittles open like clamshells?

What you need:

Skittles

Microwave-safe plate

Microwave

Alternative:

Aluminum foil-lined baking sheet

Oven

What to do:

Place the Skittles on the plate and microwave them for 1 to 2 minutes. (Alternatively, place the Skittles on the baking sheet and melt them in the oven at 350°F for about 5 minutes.)

Do the Skittles crack open like clams?

What’s happening:

Since the insides of the Skittles are soft, they contain more water than the outside sugar shells. This means the insides will soften faster when they get hot, spilling out the sides.

Do some of the Skittles open up like clamshells? Perhaps the hot candy on the inside is creating steam, which pushes up the tops of the Skittles.

Crazy Canes

Time: 10 to 30 minutes
Skill Level: Get a grown-up
The experiment: Snap! That’s what happens to your candy cane if you try to bend it. Is there a way to bend candy canes without breaking them?

What you need:

Oven

Aluminum foil

Baking sheet

Candy cane or straight candy stick

What to do:

Preheat the oven to 250°F.

Tear off a square of aluminum foil. Fold it in half, then fold again and again to make a rectangular strip about 3 inches wide (wider than the candy cane). Bend this strip into a fun shape, like a zigzag, an S-curve or a bowl.

Place the foil shape on the baking sheet and put the candy cane on the foil shape. Heat in the oven for 5 to 20 minutes. (The melting time will depend on the size of the candy cane.) Check frequently until the candy cane has softened and curved into the shape of the mold.

What’s happening:

When you’re melting an ice cube, you can see it turn to water. An ice cube is a solid, made from molecules locked together as crystals. When it melts, the molecules break apart. The solid becomes a liquid.

The molecules in a candy cane don’t make crystals. Instead, the candy cane contains lots of kinds of molecules jumbled together, like the fruit Life Saver in the Life Savers Melting Race experiment on page 96. When it gets warm, it doesn’t turn liquid right away. Instead, it gets softer and softer as the molecules shift around. That’s why you can turn a warm candy cane into a crazy cane.

In fact, your candy cane has already been heated and bent. A candy cane is made from a straight candy stick that’s bent into a cane shape while it’s still warm.